Publishing Hallo Welt internal REL2_22

This is the current state of "Hallo Welt" internal REL2_22 branch. It has
to be made available in the REL1_22 branch of the WMF. By this a end user
can download the proper version using the extension distributor on
mediawiki.org

Change-Id: I840706ba01f8349622f1c7e006c658ddde8f4e1d